When measuring our internet connection speed, probably most of us use a third-party app such as speedtest.net, or others. These work well enough for me, but I just discovered that macOS Monterrey has a built-in feature that also measures download and upload speeds. If interested in trying it out, here's the process: open Terminal; type in "networkquality" (sans quotation marks); tap return. In a few seconds the data will display. Pretty slick!
Apple says this test might differ from third party apps as they typically measure data flows up and down separately, whereas the terminal test measures both simultaneously, which may be more real-life.
Jim Hamm